/* ==========================================================================
   Undersign — navigation
   Sticky header + mobile fullscreen menu.
   ========================================================================== */

header.nav{position:sticky;top:0;z-index:60;background:rgba(242,250,247,0.88);backdrop-filter:blur(10px);border-bottom:1px solid var(--line);padding:10px 0;}
.nav-inner{display:flex;align-items:center;justify-content:space-between;padding:0 32px;max-width:var(--maxw);margin:0 auto;}
.logo{display:flex;align-items:center;gap:9px;font-family:var(--font-display);font-weight:600;font-size:1.28rem;text-decoration:none;color:var(--ink);}
.logo img{width:150px;height:auto;max-width:100%;display:block;padding:10px;}
.nav-links{display:flex;align-items:center;gap:28px;font-size:0.93rem;}
.nav-links a:not(.btn){text-decoration:none;color:var(--ink-soft);transition:color .25s var(--silk);}
.nav-links a:not(.btn):hover{color:var(--teal-700);}
.nav-links .quiet{color:var(--ink-soft);opacity:0.75;border-left:1px solid var(--line);padding-left:22px;}
.hamburger{display:none;flex-direction:column;gap:5px;background:none;border:none;cursor:pointer;padding:6px;}
.hamburger span{width:22px;height:2px;background:var(--ink);border-radius:2px;}
@media(max-width:880px){
  .nav-links a:not(.btn):not(.mobile-visible){display:none;}
  .nav-links .quiet{display:none;}
  .hamburger{display:flex;}
  .logo img{width:140px;}
}
@media(max-width:560px){
  .logo img{width:120px;}
}

/* Mobile fullscreen menu */
.mobile-menu{position:fixed;inset:0;background:var(--teal-900);z-index:100;display:flex;flex-direction:column;justify-content:center;align-items:center;gap:28px;opacity:0;visibility:hidden;transition:opacity .4s var(--silk);}
.mobile-menu.open{opacity:1;visibility:visible;}
.mobile-menu a{color:var(--seafoam-50);font-family:var(--font-display);font-size:1.7rem;text-decoration:none;opacity:0;transform:translateY(16px);transition:all .5s var(--silk);}
.mobile-menu.open a{opacity:1;transform:translateY(0);}
.mobile-menu.open a:nth-child(1){transition-delay:.08s;}
.mobile-menu.open a:nth-child(2){transition-delay:.14s;}
.mobile-menu.open a:nth-child(3){transition-delay:.2s;}
.mobile-menu.open a:nth-child(4){transition-delay:.26s;}
.mobile-menu.open a:nth-child(5){transition-delay:.32s;}
.mobile-close{position:absolute;top:24px;right:28px;background:none;border:none;color:var(--seafoam-50);font-size:1.8rem;cursor:pointer;}